Radiotherapy using a personalized blood risk score plan

Abstract

To this end, a method and system for planning radiotherapy are provided, along with a layout for radiotherapy planning and a computer program product for performing the method. To plan radiotherapy, the following steps are performed: Patient data and image data of the subject to be treated are received. The image data includes anatomical image data of one or more organs related to immune system function at risk. Next, the patient data and image data are processed to obtain a risk score for the one or more organs related to immune system function at risk. The risk score indicates the risk of hematologic toxicity in response to radiotherapy in the subject to be treated. Radiotherapy is then planned using the obtained risk score.

Description

Invention Field

[0001] This invention generally relates to planned radiotherapy. In particular, but not exclusively, this invention relates to planned radiotherapy taking into account the risk of hematologic toxicity in subjects in response to radiotherapy. Background Technology

[0002] In radiation therapy, target structures (TS) in a patient's body, such as tumors, are treated by irradiation. The radiation can be in the form of external beam radiation (such as photons) or particles (such as protons), as in external beam radiation therapy. Radiation therapy (RT) treatment aims to kill cancer cells by delivering a high dose of radiation to the tumor. Inevitably, RT delivers a dose to normal tissues, which can cause side effects. Therefore, conventional treatment delivers radiation to the TS in such a way that it is as high as possible, while simultaneously delivering as low as possible to the surrounding healthy tissues and structures, often referred to as organs at risk (OARs).

[0003] A common side effect is hematologic toxicity (HT). For example, within 30 days of undergoing radiation therapy, 50% of patients experience rapid and severe lymphopenia, which is a decrease in circulating lymphocytes.

[0004] HT is a measure of the state of the immune system. Low lymphocyte counts are negatively correlated with poorer survival. Absolute lymphocyte counts are also positively correlated with response to immunotherapy. To effectively control tumors and combine them with other treatments (such as checkpoint inhibitor immunotherapy), it is necessary to preserve the immune system, especially the T-cell subsets of lymphocytes.

[0005] One problem in current RT practice is that organs associated with immune system function, such as the thymus, active bone marrow regions, vertebrae, and large blood vessels, are rarely even considered as OARs. Even so, depending on the tumor's location, strict dose limits for different OARs associated with immune system function can be difficult to achieve in routine radiotherapy planning optimization, especially for photon radiotherapy delivery. Strict dose limits are particularly difficult to obtain for the thymus, which is located in the cardiac region.

[0006] Furthermore, conventional intensity-modulated radiotherapy guided by anatomical organ mapping can impose significant limitations on radiotherapy planning optimization, leading to increased complexity and computational time for plan generation. Additionally, optimal preservation is not known a priori.

[0007] Better tissue preservation can be achieved through non-coplanar beam placement or by using proton therapy. However, these types of radiation therapy procedures require specialized equipment and are more expensive than conventional coplanar photon delivery.

[0008] Therefore, in routine treatment, OARs associated with immune system function are often exposed to dose levels exceeding the radiosensitivity threshold. Summary of the Invention

[0009] This invention seeks to provide a radiotherapy planning method in which an oral radiation therapy (OAR) related to immune system function is considered to reduce the risk of developing HT. This invention further seeks to address the physician's need for risk scores for individual patients developing HT during radiotherapy.

[0010] To this end, a method and system for planning radiotherapy are provided, as well as an apparatus for radiotherapy planning and a computer program product for performing the method.

[0011] A method for planning radiotherapy includes the steps of receiving patient data from a subject to be treated and receiving image data from the subject to be treated. The image data includes anatomical image data of one or more organs associated with immune system function at risk. The method also includes the step of processing the patient data and image data to obtain a risk score for the one or more organs associated with immune system function at risk. The risk score indicates the risk of hematologic toxicity (HT) in the subject to be treated in response to radiotherapy. The method also includes the step of using the obtained risk score to plan radiotherapy treatment to reduce the risk of hematologic toxicity in the subject to be treated.

[0012] One or more organs at risk related to immune system function may be, for example, one or more of the following: thymus, active bone marrow region, vertebrae, heart, heart chambers or major blood vessels.

[0013] Preferably, the subject's image data also includes functional image data of one or more organs at risk related to immune system function, wherein the risk score is obtained by applying a functional model of the at-risk organ. One advantage of including functional image data is that highly functional regions of immune system organs, such as, for example, active bone marrow and thymus tissue, can be identified, and preservation of these regions can be improved when the risk score for such regions is high.

[0014] Preferably, the risk score is obtained by applying a model based on historical patient data. Additionally or alternatively, patient data may include blood cell counts in the subject, particularly lymphocyte counts. Information such as lymphocyte counts can be particularly relevant when the patient is envisioned to be further treated with some form of immunotherapy.

[0015] In a preferred embodiment, the radiotherapy planning process includes selecting the type of radiotherapy, such as one of the following: intensity-modulated radiotherapy (IMRT), volume-modulated radiotherapy (VMR), photon radiotherapy with a non-coplanar beam arrangement, or particle therapy (e.g., proton therapy); and calculating a radiotherapy plan for the selected type of radiotherapy. The advantage of this is that it allows physicians to select expensive treatments, which involve lengthy and complex planning procedures, such as proton therapy and non-coplanar radiotherapy, for cases where the physician would benefit most from their additional alternatives. For cases where the risks are within acceptable limits, more conventional photon radiotherapy, such as VMAT, can be selected.

[0016] In another preferred embodiment, which can be combined with other embodiments and preferences, the image data further includes anatomical image data of at least one target structure, and the method further includes receiving clinical targets for the target structure and one or more organs at risk.

[0017] Another possibility is to use the obtained risk score to adjust clinical goals when planning radiotherapy treatment.

[0018] On the other hand, planning a radiotherapy treatment may include calculating an organ preservation probability score for one or more organs at risk related to immune system function for each of a set of possible radiotherapy treatment options. This can be particularly advantageous when the radiotherapy treatment options are different geometric beam arrangements in intensity-modulated radiotherapy.

[0019] The system for planning radiotherapy includes inputs for receiving patient data from a subject to be treated, and inputs for receiving image data from the subject to be treated. The image data includes anatomical image data of at least one organ associated with immune system function at risk. The system also includes a risk score calculation unit and a radiotherapy planning unit. The risk score calculation unit is configured to process the patient data and image data to obtain a risk score for one or more organs associated with immune system function at risk, indicating the HT risk of the subject to be treated in response to radiotherapy. The radiotherapy planning unit is configured to select a radiotherapy plan using the obtained risk score to reduce the hematologic toxicity risk of the subject to be treated.

[0020] In one embodiment, the system further includes a display unit configured to display a risk score for at least one organ at risk. Preferably, the display is also configured to display an organ preservation probability score for each group of possible radiotherapy options for organs at risk related to immune system function. Such embodiments have the advantage of providing physicians or planning technicians with a convenient overview to inform and / or assist in making decisions regarding treatment plans.

[0021] The setup for radiotherapy planning includes one or more imaging devices configured to generate image data of the subject to be treated, a patient information database configured to store and provide patient data, and a system for planning radiotherapy as described above.

[0022] Further aspects are described with reference to the appended claims and exemplary embodiments.

[0023] One advantage of this invention is that it reduces the risk of hematologic toxicity due to radiotherapy. Therefore, it can provide better treatment outcomes for general patients, especially those undergoing radiotherapy in combination with immunotherapy.

[0024] Another advantage is that physicians can plan more personalized clinical goals in the radiotherapy program.

[0025] Another advantage is that it allows for better preservation of organs at risk that are related to immune system function.

[0026] Another advantage is that it allows for prioritizing restrictions on organs at risk related to immune system function and avoiding unnecessary strict restrictions, thus providing more effective radiation therapy planning calculations. Attached Figure Description

[0027] In the following figures:

[0028] Figure 1 Additional components of a system for planning radiotherapy and an arrangement for planning radiotherapy are illustrated schematically and exemplary.

[0029] Figure 2 An example of a method for planning radiotherapy is illustrated schematically.

[0030] Figure 3 An example illustrating the processing of patient and image data to obtain risk scores for organs at risk related to immune system function.

[0031] Figure 4a and Figure 4b An example of a display showing risk scores for organs related to immune system function that are at risk is illustrated.

[0032] Figure 5a The functional image data of the subject to be processed is schematically shown, and Figure 5b A functional reference image is shown schematically.

[0033] Figure 6An example of a method for planning radiotherapy is illustrated, which includes calculating an organ preservation probability score for a set of possible radiotherapy treatment options.

[0034] Figure 7 The illustration schematically shows a display of risk scores for organs at risk related to immune system function, as well as alternative options for different possible radiotherapy treatments. Detailed Implementation

[0035] Figure 1 A system 110 for planning radiotherapy is shown. In this example, the system is shown as part of an arrangement 100 for planning radiotherapy. In addition to the system 110 for planning radiotherapy, the arrangement includes an imaging device 120 and a patient information database 130.

[0036] Imaging device 120 is configured to generate image data of the subject. Imaging device 120 may be a single unit for medical imaging, but more imaging devices may be used to acquire data. The acquired images may be computed tomography (CT) images, magnetic resonance (MR) images, positron emission tomography (PET) images, another medical image, or a combination of images, such as a combined PET / CT or PET / MR image. Figure 1 As an example, a combined PET / CT imaging setup 121 is shown. In the images, a contouring tool 122 is used to delineate at least one organ at risk associated with immune system function (OARIS) to provide anatomical image data for the OARIS. Typically, the region of interest in the subject will include at least one target structure (TS), usually a tumor, and may also include more OARIS and other OARs.

[0037] Preferably, all TS, OARIS, and OAR are delineated to provide their anatomical image data. Contouring tools, such as 122, are typically interactive with the user, who can be, for example, a trained medical imaging technician or radiologist, to define the contours of the region of interest. This process can be entirely manual or partially or fully automated.

[0038] Anatomical image data 123 can be combined with additional image data that can be used in planning RT. Preferably, the image data also includes functional image data obtained from, for example, PET or SPECT imaging devices. As shown here, image data 124 can be used directly in planning system 110, but is more commonly stored in databases such as picture archiving systems (PACS) or hospital information systems (HIS) for easier access.

[0039] The patient information database 130 is configured to store and provide patient data. Typically, patient data is stored in electronic medical records (EMRs). This data can be any previously collected and stored information about the subject to be treated. The data can be personal data such as sex, age, height, or weight. It can also be medical data such as blood panel data and baseline lymphocyte counts, or information about side effects that occurred during previous treatments.

[0040] The system 110 for planning radiotherapy (RT) has an input 111 for receiving patient data of the subject to be treated and an input 112 for receiving image data of the subject to be treated. In this example, patient data is received fully automatically from a patient information database 130. Alternatively, data may be entered manually, or partially manually and partially received from database 130. The received image data 124 includes anatomical image data 123 of at least one OARIS. The RT planning system 110 also includes a risk score calculation unit 113 and a radiotherapy planning unit 114. The risk score calculation unit is configured to process the patient data and image data to obtain a risk score of one or more OARIS, which indicates the HT risk of the subject to be treated in response to radiotherapy. When the image data includes functional image data, the risk score is preferably a functional risk score obtained by using that data. The risk score can be obtained, for example, by applying a functional model of OARIS. Figure 1 In one example, the arrangement also includes an optional display unit 140 configured to display at least one OARIS risk score.

[0041] The radiotherapy planning unit 114 is configured to plan radiotherapy treatment using the obtained risk score. The planned RT treatment can be performed automatically according to predefined criteria, but can also be performed interactively by the user. Users of this system are typically radiation oncologists or radiotherapy planning technicians. For example, the planned RT treatment may include selecting one of the following: intensity-modulated radiotherapy (IMRT), volume-modulated radiotherapy (VMAT), photon radiotherapy with a non-coplanar beam arrangement, or particle therapy such as proton therapy; and calculating a radiotherapy plan for the selected radiotherapy type.

[0042] Calculating and optimizing RT processing plans is typically an interactive process with the user. To achieve this, the RT planning unit 110 advantageously has a user interface, preferably a graphical user interface (GUI). The display 140 can be integrated with such a GUI.

[0043] Figure 2The steps of a method for planning radiotherapy 200 are illustrated schematically. Following the method for planning radiotherapy is an additional method step 150 for adjusting the RT plan during treatment.

[0044] The method for planning RT 200 includes a step 210 of receiving patient data of the subject to be treated and a step 220 of receiving image data of the subject to be treated. The image data includes anatomical image data of one or more OARIS. The image data may be generated as described above with respect to imaging apparatus 120. The method also includes a step of processing the patient data and image data to obtain a risk score 230 of one or more OARIS. The risk score indicates the risk of HT in the subject to be treated in response to radiotherapy. The method also includes a step 240 of planning RT treatment using the obtained risk score.

[0045] In an optional supplement to method 250, the subject to be treated may be monitored during treatment to determine whether the risk of HT remains within acceptable limits. If not, the physician may decide to adjust the treatment accordingly or take additional measures to mitigate the side effects of the treatment.

[0046] In the method used for planning RT 200, a risk score for one or more OARIS is calculated before RT treatment (pretreatment) is performed. RT treatment is typically performed in several instances called fractions, with a recovery period between each fraction. In an additional method, at step 251, the RT score is delivered to the subject. After delivery, the risk score for one or more OARIS is updated 252 to determine the current risk of HT. The updated score is determined in a similar manner to that done at step 230, but based on updated patient data and / or updated image data. The updated image data may come from, for example, setup images taken immediately before treatment delivery, or images from the additional arrangement. For patients treated with a hybrid system combining MRI or PET imaging with a radiotherapy delivery device, updated functional images may be acquired at the hybrid unit before treatment delivery. The updated patient data may be, for example, updated blood panels or updated lymphocyte counts.

[0047] A series of updated scores can be used to monitor subjects during treatment and post-treatment. A beneficial additional option is to examine each updated risk score to determine if the risk of HT due to continued treatment remains within acceptable limits. If so, indicated by "Yes," the treatment can proceed to the next score. If the risk of HT is too high, indicated by "No," the physician can decide to return to the planned treatment, but now using a smaller risk score.

[0048] Figure 3An example of processing patient and image data to obtain an OARIS 300 risk score is shown. In this example, the risk score for the thymus is calculated.

[0049] The thymus, located at the base of the heart, primarily functions to promote the differentiation of bone marrow-derived lymphocyte progenitors into mature T cells. Deterioration of thymic function leads to increased susceptibility to infectious diseases. Minimizing damage to the thymus is crucial for the recovery of T cell reproliferation after radiotherapy (RT). Even low-dose ionizing radiation used in RT can accelerate thymic deterioration. Furthermore, immature T cells located in the thymus are among the most radiation-sensitive cells in the human body. Therefore, considering the thymus as an OARIS (Oxygen-Oxygen-Related Response Syndrome) is particularly advantageous, especially when RT treatment is combined with immunotherapy. A thorough understanding of the thymus's risk score, which indicates the risk of developing HT (Hyperthermia) in subjects awaiting treatment in response to RT, is also beneficial.

[0050] Figure 3 Various options for obtaining a HT risk score for the thymus are shown. First, prior to treatment, planning images 310, including the thymus region, are obtained for the subject to be treated. Radiographic thymus parameters 315 are determined by analyzing the images. This can be accomplished by shaping the thymus contour and determining its size and shape.

[0051] Alternatively or additionally, tissue composition, particularly the fat content of the thymus, can be determined, for example, from MRI images. Alternatively or additionally, metabolic function or cell proliferation can be determined from PET images using appropriate radiotracers.

[0052] The physiological thymus score (PTS) 340, reflecting thymus function in an individual patient, can now be determined. In principle, radiological information is sufficient and will produce a radiological PTS. However, accuracy can be improved by including additional patient information. For example, blood panel information, including lymphocyte counts, can be received as input 320 for PTS determination. Furthermore, a historical patient model 330 can be used. Such a model provides the distribution of radiological PTS across a population of healthy individuals according to age groups. As input, this model receives the age of the subject to be treated as input data 335.

[0053] When a subject's PST score is determined based on available information and models, a risk score of HT due to RT treatment is derived as 350. As a supplement and alternative to the HT risk score, indicators of the likelihood of immune system recovery, particularly the likelihood of lymphocyte population recovery, can be derived. Good immune system recovery is associated with a better likelihood of long-term survival and better success with subsequent treatment using immunotherapy. A low chance of recovery can be an indicator of long-term or even chronic HT, which may require additional care from the treating physician.

[0054] The results of the calculation are preferably displayed 360 degrees to the physician or RT planning technician. Advantageously, the display provides a warning, for example, by highlighting it in red, when the thymus risk score is higher than a predefined level.

[0055] The calculation of PTS, thymus risk score, and recovery probability can be repeated after each treatment score is delivered to the subject. This will allow physicians to monitor the patient's condition and make changes to the treatment as necessary.

[0056] Figure 4a and Figure 4b An example of a display showing a risk score related to immune system function at risk is illustrated.

[0057] Figure 4a This is a pre-treatment thymus scoreboard 400 for three different subjects P1, P2, and P3 who require RT treatment. The scoreboard shows the baseline lymphocyte class 401 for each subject in the first column. For each subject, these classes are derived from the pre-treatment blood panel and are indicated by M, signifying moderate. The PTS (Probability of Recovery) was also calculated for each patient. The PTS 402 is also shown in the second column, based on the class L (low), M (moderate), and H (high). A low score indicates poor thymus function, while a high score indicates good thymus function. The probability of immune system recovery 403 is shown in a similar manner in the third column. Figure 4a The scoreboard informs physicians that the PI will not benefit from additional thymus preservation and therefore the RT plan can be completed with more lenient OARIS clinical goals. Patients P2 and P3 will benefit from additional thymus preservation, and clinical goals should be set accordingly for these patients.

[0058] Figure 4b The patient RT monitoring report 450 is shown, also for three different patients P1, P2, and P3. The first column shows the lymphocyte ratio of the current lymphocyte count to the pretreatment lymphocyte count 451. The second column shows the PTS ratio of the current PTS to the pretreatment PTS 452. As can be seen, although the lymphocyte count ratio is the same in all three patients, the changes in PTS are different. PTS provides important additional information about the state of the immune system of the treated subjects. Figure 4b It was also shown that P3 is a high-risk group for long-term HT, after the immune system in P2 has a good chance of recovery.

[0059] Figure 5a The functional image data of the subject to be processed is schematically shown, and Figure 5b A functional reference image is shown schematically.

[0060] Figure 5aFunctional PET images are shown, which allow for the identification of active bone marrow in subjects from standard uptake values ​​(SUVs) in the images. Several tracers are suitable for visualizing active bone marrow regions; for example, 18-F-FDG will show metabolic turnover, and 18F-FTL provides information on cell proliferation, as well as anti-CD8 PET tracers, which allow for the direct labeling of CD8 lymphocytes. Figure 5a This is an FLT-PET image. In this image, dark gray corresponds to high tracer uptake, while light gray corresponds to low tracer uptake. As can be seen, in this subject, active bone marrow regions are located in the pelvic bones 501 and sternum 502, particularly in the spine 503.

[0061] Bone marrow activity decreases with age, so a reference model can be provided by taking statistical averages for each age group based on historical patient data. Figure 5b It shows the relationship with Figure 5a This is the average value for subjects of similar age. Again, here, dark gray represents active bone marrow areas, while light gray represents inactive bone marrow. The outer contours of the reference subjects are shown in white. Figure 5b The reference model also shows active bone marrow in the pelvis 551, sternum 552, and spine 553. The model also shows... Figure 5a Active bone marrow was absent in the upper arm 554 of the subjects.

[0062] For active bone marrow like OARIS, the risk score can be taken as the ratio of active bone marrow within the radiation field to the total active bone marrow outside the radiation field. Alternatively, the risk score can be taken as the ratio of active bone marrow in the subject to a reference model of the subject's age.

[0063] In another example, risk factors can be identified for OARIS (Oxygen Flow Intake) and cardiac structures near large blood vessels close to the heart. For this purpose, personalized blood flow measurements can be obtained using, for example, Doppler echocardiography or MRI T1-weighted perfusion imaging, and these personalized measurements are combined with a blood panel at a baseline that provides the number of different white blood cell populations (neutrophils, lymphocytes, etc.) per unit volume. This allows for estimation of the number of white blood cells that will be exposed during radiation, which can be high or low relative to a standardized value. One advantage of using MRI T1-weighted perfusion imaging is that it can be obtained through a hybrid MR RT linear accelerometer system, enabling personalized blood flow measurements at each processing fraction.

[0064] Figure 6An embodiment of a method for planning radiotherapy 600 is shown, which includes an organ preservation probability score for a set of possible radiotherapy treatment options. Such a set could be a group of treatment types, where the risk score is used to select the appropriate treatment type. However, in the current example, IMRT has already been selected for RT treatment, but a selection still needs to be made from a set of different geometric beam arrangement options.

[0065] Prior to the RT planning method 600, image data related to the subject to be treated has been acquired. The imaging data in this embodiment includes anatomical image data of one TS and one or more OARIS. The image data also includes planning CT images and functional FDG PET images of the subject acquired prior to treatment.

[0066] As part of the planning methodology, 610 patient data related to the subjects to be processed and 620 image data are received. The data 630 are then processed to obtain OARIS risk scores. In this example, functional image data are used to calculate a functional risk score for each OARIS.

[0067] After obtaining risk scores for one or more individual OARIS, IMRT processing is performed using the risk score plan 660 of this exemplary embodiment. In the processing plan, a first retention probability for each of the one or more OARIS is calculated for each treatment option using the functional risk score. For this purpose, 650 different options are provided, in this example, geometric options for beam arrangement. Dose characteristics are also considered as part of the retention probability calculation. Such characteristics can be based on clinical goals for the OARIS, such as average dose, maximum dose, and the volume of OARIS receiving a dose above a predetermined level. In this embodiment, clinical goals are provided at 640. Clinical goals can be manually specified and entered by a physician or planning technician, or they can be received from a database, such as values ​​based on a standardized processing protocol.

[0068] The retention probability of OARIS can be derived by calculating a retention probability metric. This metric can be determined using several methods, such as calculating the number of sub-bundles in the treatment plan that will cross the OARIS during treatment, and the ratio of the OARIS volume intersecting with the sub-bundles to the total volume. Alternatively, an AI component, including, for example, a Bayesian network or neural network, can be trained using historical patient data and used to determine the current retention probability. The following is an alternative example of personalization for the subject to be treated. The retention probability p, taking into account the probability of developing HT, can be defined by the following relationship:

[0069]

[0070] In this equation, X represents non-dose characteristics associated with HT, such as the subject's age, pre-treatment blood cell count, thymus radiographic score, active bone marrow volume, and / or the type of chemotherapeutic agent in the case of combined RT and chemotherapy. The parameter Yj represents the dose characteristic of the RT treatment plan. Further in this equation, a0 is a constant factor, bi is a coefficient representing the relative importance of each non-dose OARIS risk score, and cj is a coefficient representing the relative importance of the dose characteristic Yj. The coefficients a0, bi, and cj can be determined by fitting a logistic regression model to the population data.

[0071] For the subjects to be treated, the value of the non-dose characteristic Xi ​​will be known before treatment begins. However, different RT plan options with different dose distributions will result in different values ​​for the dose characteristic Yj. This can be represented as follows:

[0072]

[0073] In this equation, k represents a planning option, which could be a dose distribution 1,2,…,k or a geometric beam arrangement 1,2,…,k. The dose characteristic Yjk is the dose characteristic of a specific option k, and the retention probability index pk represents the retention probability specific to that option.

[0074] The dose characteristics of the dose distribution or beam arrangement can be approximated from the beam arrangement, predicted from a database of pre-calculated plans, or derived from a previously fully optimized plan for the patient. Using an approximate dose distribution or a database-predicted plan is advantageous because it improves computational efficiency. In these cases, only the complete RT plan with optimal OARIS retention will be fully calculated and optimized.

[0075] After obtaining the risk score and retention probability, select the 670 beam arrangement for IMRT. Among the alternatives, if none of the geometric beam arrangements are satisfactory, the user can roll back from 655 to 650 to provide another alternative beam arrangement and recalculate the retention probability at 665.

[0076] Preferred beam arrangements can be automatically selected using predefined criteria 675, or can be entered by the physician or planning technician. For the purpose of reviewing the options, the OARIS risk score and its retention probability for various beam arrangement options are displayed. Using the displayed information, the physician can also decide to modify one or more clinical goals 685 to improve the retention of OARIS for high-risk HT, or to make the clinical goals less stringent for the retention of OARIS for low-risk HT.

[0077] After the beam arrangement was selected and the clinical objectives were optionally modified, the RT treatment plan was fully calculated and optimized.

[0078] Figure 7 An example is provided showing a display of the OARIS risk score and alternative options for different possible radiotherapy treatments.

[0079] In this example, the information is presented in the form of data table 710. When the display is part of an interactive planning system, this table can be part of a GUI, allowing users to click on individual fields to access additional information and / or select preferred processing options for calculating the final processing plan to be delivered.

[0080] The subject shown in 710 has a lung tumor located near the vertebrae. In this subject, FDG PET scans have shown that most of the active bone marrow is located in the thoracic vertebral region, which is within the initial radiation range of RT treatment. Therefore, the risk factor for active bone marrow is high. In this subject, the thymus size is within the expected range for age, and the baseline lymphocyte count is normal. The resulting thymic risk is high.

[0081] The exemplary information shown in Table 710 illustrates information for intensity-modulated radiotherapy (IMRT) with two possible beam geometries. The rows of the table represent the associated OARIS, which in this case are four: bone marrow OARIS1, thymus OARIS2, cardiac chamber OARIS3, and great vessel OARIS4. Column 2 shows the risk score 715 obtained for each OARIS. Preferably, this risk score is a functional risk score. The risk score value is between 0 and 1, where 0 is the lowest risk and 1 is the highest risk. Column 3 shows the retention probability of the first IMRT beam arrangement 720, and column 4 shows the retention probability of the second beam arrangement 725. The retention probability is indicated by the symbols L for low, M for moderate, and H for high. Additionally or alternatively, traffic light colors can be used to highlight the table, where green indicates low, yellow for moderate, and red for high.

[0082] like Figure 7 As can be seen, the bone marrow OARIS1 and thymus OARIS2 responses to radiotherapy carry a high risk of inducing HT, while the risk to the cardiac chambers and vessels is low. From the monitor, radiation oncologists or planning technicians understand that the first beam arrangement 720 places the bone marrow at significant risk, and therefore the second beam arrangement 725 is preferred. The second beam arrangement is selected to continue with the full calculation and optimization of the IMRT treatment plan.

[0083] Any method steps disclosed herein can be recorded in the form of a computer program including instructions that, when executed on a processor, cause the processor to perform such method steps. The instructions can be stored on a computer program product. The computer program product can be provided by dedicated hardware and hardware capable of executing software associated with suitable software. When provided by a processor, these functions can be provided by a single dedicated processor, a single shared processor, or multiple separate processors, some of which may be shared. Furthermore, embodiments of the invention can take the form of a computer program product accessible from a computer-usable or computer-readable storage medium that provides program code for use by or in connection with a computer or any instruction execution system. For the purposes of this description, a computer-usable or computer-readable storage medium can be any device that can include, store, communicate, propagate, or transmit programs for use by or in connection with an instruction execution system, device, or apparatus. The medium can be electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or apparatuses or propagation media. Examples of computer-readable media include semiconductor or solid-state memory, magnetic tape, removable computer floppy disks, random access memory (RAM), read-only memory (ROM), hard disks, and optical disks. Current examples of optical discs include optical disc read-only memory "CD-ROM", optical disc read / write "CD-R / W", Blu-Ray™ and DVD. Examples of distribution media are the Internet or other wired or wireless telecommunications systems.

[0084] By studying the accompanying drawings, this disclosure, and the appended claims, those skilled in the art can understand and implement variations of the disclosed embodiments in practicing the claimed invention. Note that various embodiments can be combined to achieve further advantageous effects.

[0085] In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plural.

[0086] A single unit or device can perform the functions of several items listed in the claims. The fact that certain measures are listed in different dependent claims does not mean that a combination of these measures cannot be used advantageously.

[0087] Any reference symbols in the claims should not be construed as limiting the scope.

Claims

1. A computer-implemented method for planning radiotherapy, the method comprising: - Receive patient data from subjects to be processed; - Receive image data of the subject to be processed, the image data including anatomical image data of one or more organs related to immune system function at risk; - Process the patient data and the image data to obtain a risk score for one or more organs associated with the function of the immune system at risk, the risk score indicating the risk of blood toxicity in the subject to be treated in response to the radiotherapy; as well as - The obtained risk score is used to plan the radiotherapy treatment to reduce the risk of blood toxicity in the subjects to be treated.

2. The method of claim 1, wherein the image data of the subject further includes functional image data for the one or more organs at risk related to the function of the immune system, and wherein the risk score is obtained by applying a functional model of the organs at risk.

3. The method of claim 1, wherein the risk score is obtained by applying a model based on historical patient data.

4. The method according to any one of claims 1-3, wherein the patient data includes blood cell counts in the subject.

5. The method according to any one of claims 1-3, wherein the patient data includes lymphocyte counts in the subject.

6. The method according to any one of claims 1-3, wherein the one or more organs at risk related to the function of the immune system are at least one of the following: thymus, active bone marrow region, vertebrae, heart, cardiac chambers or major blood vessels.

7. The method according to any one of claims 1-3, wherein the planned radiotherapy treatment comprises: Choose the type of radiation therapy; And to calculate the radiotherapy plan for the selected type of radiotherapy.

8. The method according to any one of claims 1-3, wherein the image data further comprises anatomical image data of at least the target structure; and the method further comprises receiving the target structure and clinical targets of the one or more organs at risk.

9. The method of claim 8, wherein planning the radiotherapy treatment includes adjusting the clinical goals using the obtained risk score.

10. The method of claim 8, wherein planning the radiotherapy treatment includes, for each of a set of possible radiotherapy treatment options, calculating an organ preservation probability score for the one or more organs at risk related to the immune system function.

11. The method of claim 10, wherein the radiotherapy treatment option is a different geometric beam arrangement in intensity modulated radiotherapy.

12. A system for planning radiotherapy, comprising: - Input for receiving patient data from subjects to be processed; - Input for receiving image data of the subject to be processed, the image data including anatomical image data of at least one organ related to immune system function at risk; - A risk score calculation unit configured to process the patient data and the image data to obtain a risk score for one or more organs related to the function of the immune system that are at risk, the risk score indicating the risk of blood toxicity in the subject to be treated in response to the radiotherapy; - A radiotherapy planning unit configured to select a radiotherapy plan using the obtained risk score to reduce the risk of blood toxicity in the subject to be treated.

13. The system of claim 12, further comprising a display unit configured to display the risk score of the at least one organ at risk.

14. The system of claim 13, wherein the display unit is further configured to display an organ retention probability score of the organ at risk in relation to the function of the immune system for each of a set of possible radiotherapy options.

15. An apparatus for radiotherapy planning, comprising: One or more imaging devices, the one or more imaging devices being configured to generate image data of a subject to be processed; A patient information database, configured to store and provide patient data; as well as The system for planned radiotherapy according to any one of claims 12-14.

16. A computer program product comprising instructions for causing a processor to perform the method according to any one of claims 1-11 when the computer program is executed.

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